1998 3.0v6
I thought I had this fixed a month ago and now she has the same code P1074 with what feels like a misfire. It will stumble almost like a fuel cutoff when you hit that 115 mph in the old Camaros. The stumble only happens after 30 min of driving and is intermittent. I wish it would just always miss so I could track it down more easily. The miss is more prevalent at low RPM but I can feel it missing at high rpm too.

New plugs and wires

No vacuum leaks

New o2 in bank 2

Cleaned MAS

New fuel filter

New Air filter

Cleaned throttle body

 

Welcome to the forum

I assume you mean P0174 lean exhaust on Drivers side of V engine

The mis-fire itself can cause that code, O2 sensor only sees Oxygen, Lean means too much oxygen in the exhaust on that side/bank of the engine.
When a cylinder mis-fires no oxygen is burned up so it is all dumped into the exhaust on that bank, which sends oxygen levels up, and Lean code is set.

I would pull spark plugs on that bank, have a look at the tips, see if you can ID which one is mis-firing.
What I might do first is to disable the coil pack, unplug 4 wire connector, and then crank the engine over a few times.
Then pull out those 3 spark plugs, all the tips should be EQUALLY WET with fuel, if you find one that is DRIER then that injector may be getting plugged up or failing.

Also just see if one tip is showing less wear, lighter color than the others, and swap out that 1 spark plug.
I have gotten bad spark plugs before, not common but certainly possible

 

Thanks RonD sounds like a good place to start, too bad it’s not on the opposite side. Going to need to pull the upper intake if it’s an injector on that side. They do have a ton of miles on them would not be surprised at all if it was an injector.